Tension indicator



, Dec. .29, 1931.' R w k. 1,838,299

TENSION INDICATOR Filed Sept. 19, 1929 1520 6433??? 3 V fgwsi' 2? 62916.I W"- 777 Patented Dec. 29,1931

UNITED STATES IPA-TENT. orrics ERNEST 2. COOK, OF BERLIN/NEW HAMPSHIRE,ASSIGNOB T0 BROWN COMPANY, .OF

BERLIN, NEW HAMPSHIRE,

A conronA'rIoN or MAINE TENSION INDICATOR Application flied September19, 1929. Serial No. 393,648.

This inventionrelates to a portable device for testing the tension on astationary or.

moving strand. While the invention is applicable to strands in general,it is hereinafter described more particularly with reference to a wetthread movin upwardly from a bath of acid or other liqui as for'examplea rayon filament emerging from the initial setting bath in the course ofmanufacture.

One of the many methods of -manufacturing so-called artificial silkcomprises the extrusion of fine filaments of viscose through the holesof a spinneret into an acid solution which sets the liquid viscose atonce. The

are usually from forty to sixty in number, are collected together afterpassing through the setting bath and are thereafter handled as a singlethread. It has been found that if the filaments are stretchedimmediately after setting, this stretching materially increases thestrength of the thread. The filaments may be stretched by passing thethread through the setting bath over two successive feed rolls, thesecond feed roll having a greater peripheral speed than the first. Thisresults in a drawing or stretching action on the stretch of threadbetween the two rolls. The amount of stretch can be regulated bycontrolling the relative peripheral' speeds of the rolls. In order toobtain a uniform product having the highest available" strength, it isnecessary that the tension on the thread between the two rolls becarefully regulated.

The present invention is intended to su ply a portable testing devicewhich may e quickly and easily applied to astretch of thread between thefeed rolls to determine whether the tension on the thread is of desiredmagnitude. A further object of the invention is to provide atension-indicating device particularly adapted. for use with strands Wetwith acid or other corrosive liquid. To this end. the parts are shapedand arranged to avoid as far as possible communication of the acid fromthe thread-err gaging elements of the device to the other parts. In theconstruction of the device, furthermore, delicate parts liable to berendered inoperative or inaccurate by corrosion are avoided. Thedeviceillustrated as an embodiment of the invention comprises a handle havinga forked extension on an end thereof, this forked extension comprising'apair of parallel disks carryin a rotatable drum between them. A pair 0glass contact members of suitable shape are mounted on the edges of thedisks in a line parallel to the axis of the drum. A third glass memberis mounted on the periphery of the drum and is movable by a finger pieceto a position wherein a stretch of thread is receivable so as to be .111contact with the three balls simultaneousfine filaments from .a singlespinneret, which 1y. In order to guide the thread as it is tested, eachcontact member is provided with a peripheral groove. A spring isprovided to actuate the drum so as to move the middle member to bend thethread iii contact there with. The extent of bend depends upon thetension of the thread and is a measure thereof, this extent of bendbeing indicated by a suitable scale which may be carried either by thedrum or by one of the disks.

For a complete disclosure of the invention, reference is had to thedescription thereof which follows and "to the drawings, of which,-

Figure 1 is a plan view of a device embodying the invention. 7

Figure 2 is a section on the line 2-2 of Figure l.

Figure 3 is an end elevation of the. device.

Figure 4 is a side elevation of a portion of the device.

Figure 5 is a perspective view of the axle of the drum.

Figure 6 is a perspective view of a spring for rotating the drum.

The device includes a suitable handle member 10 having a forkedextension at one end comprising a pair of arallel disks 11, 12, thesedisks being suita ly spaced to receive a drum l3 therebetween. Thesemembers may be made of any suitable material, such as a phenoliccondensation product, which is resistant to corrosion by acidsor otherchemicals. A pivot member 14 is screw-threaded centrally through thedisk 11 with a tight fit. A second pivot member 15 is screw-threadedwith a ti ht fit in a suitable bushing 16 which extends t rough acentral aperture in the disk 12. As shown in Figure 2, a portion of thedisk 12 and of the neck connecting the disk with the handle member 10 isslotted as at 17. A draw screw 18 extends across the slot 17, thepurpose of this screw being to draw the elements on either side oftheslot together to clamp the bushing 16 tightly in place. The drum 13 maybe hollowed as at 19. An axle is mounted within the drum 13, this axlehaving a squared portion within the hollow 19, and recessed ends toreceive the pivot points of the members 14 and 15. A. helical spring 21is housed within the hollOw of the drum 13, the turns of this springbeing large enough to pass around and to clear the axle 20. The springis preferably made of as heavy stock as possible within the limitationsimposed on length, size of coils, and tensions to be measured, tominimize the effects of surface corrosion on its action. The spring,axle, and pivot members are preferably made of a suitable metal ormetals, such for example as bronze or Monel metal, which are resistantto corrosion by the acid or other liquid which the instrument is liableto encounter in service. One end of the spring 21 is formed in squareshape as at 22 so as to fit closely on the squared portion of the axle20. The opposite end of the spring 22 is preferably secured to thebushing 16 as by soldering. Rotation of the drum is thus yieldinglyopposed by the spring 21, since one end of the spring is anchored to Ithe fixed bushing 16, while the other end is turned by the squaredportion of the axle which rotates with the drum 13. In order 3 'to limitthe angle of rotation of the drum 13, a pair of suitable pins 23 and 24are provided, these pins extending radially from the periphery of thedrum in such a way as to engage the handle portion 10 as shown inFigure 1. The bushing 16 may be provided with a slot 25 in the outer endthereof by whichthe bushing may be adjustably turned, the draw screw 18being backed off sufficiently for this purpose. The screw 18 isthereafter set up tightly when the bushing 16 has been suitablyadjusted. Angular rotation of the bushing 16 regulates the tension ofthe spring 21 exerted on the drum 13 when the drum is in the positionillustrated in full lines in Figure 1. V,

Mounted on the edges of the disks 11 and 12 are a pair ofthread-engaging members 26 of substantial axial length and diameter.These members may be in the form of glass balls or equivalent shapes,each having a peripheral groove 27. The members 26, as shown on thedrawings, may be fixed to bronze bolts 28 which are in screw-threadedengagement with the disks so as to permit removal and replacement of theballs 26. The members 26 are arranged in a line substantially parallelto the axis of the pivots 14, 15 and the drum 13. Between the members 26a preferably similar member 29 is carried by the drum 13. This memberalso has a peripheral groove 27 The grooves 27 are prefer ably arrangedas shown in planes which are perpendicular to the radially extendingbolts carrying the respective members. The pin 24 is preferably soarranged that when it is against the handle 10, the member 29 occupiesthe position shown in dotted lines in Figure 1, and the members 26 and29 are then capable of receiving in their grooves a stretch of thread.When the members are in this position, they also overlap slightly sothat when the stretch of thread is introduced into the grooves 27, itwill be stopped therein. The members 26 and 29 are designed for use witha traveling strand or thread which is wet with acid or other corrosiveliquid. These members are therefore shaped in such a way as to preventas far as possible communication of acid to the other parts of thedevice whem the device is in its usual position of use and when it ishung up. When in use, the members 26 and 29 are one above another. Thusthe wet strand contacts with a side of each of the members. Since themembers illustrated on the drawings are so shaped that the point ofcontact is substantially removed from the pin or bolt which supports themember, and the member is of considerable diameter so that its lowestpoint is well below the supporting pin, liquid which rubs off the threadis led to the lowest point of the member and drips off without goingnear the pin. This tends to keep the liquid confined to the contactmembers. The surfaces of the members 26 and 29 remote from the drum 13project from the grooves 27 so that when the mechanism is ready toreceive a filament for testing, these surfaces cooperate to form aconverging guide to facilitate the introduction of the filament into thegrooves 27, as in icated in Figure 1. These surfaces also serve to leadaway liquid from the grooves when the device is hung up after use, andto facilitate dripping of such liquid therefrom. The spherical formillustrated on the drawings is an effective and desirable shape for themembers 26 and 29, but it is understood that this shape may be variedwithout exceeding the sco e of the invention. The spring 21 is preerably so adjusted as toimpress a torque on the drum 13 tending torotate the drum from the dotted position shown .in Figure 1 to the fullline position illusnesaaea preferably adjusted so that it will bebalanced by tension on the thread when the drum is substantially in theposition illustrated in Figure 1 in full lines.

The device is designed for use on vertically traveling threads so-thatthe weight of the movable member29 need not be considered.

m In using the device, the handle 10 is gripped in the hand, a fingerbeing used to press the pin 24: against the end of the handle member soas to rotate the drum into the position illustrated in dotted lines inFigure 1. The device is then held in such a position that the verticalstretch of thread is in contact with the grooves 27. The pin 24 is thenreleased by the finger permitting the drum 13 to rotate under the actionof the spring 21 until the spring is balanced by the tension of thethread acting on the balls 26, 29 in a direction opposed to the torqueof the spring. After use, the device is adapted to be hung up to letacid or other liquid which may be on the members 26, 29 driptherefrom,,an aperture or eye 30 being provided for this purpose. Inorder to indicate the amount of tension on the thread, a suitable scale31 may be the furcations respectively,-

marked on the drum to cooperate with an index 32 on. one of the disks11, 12. If preferred, the scale may be on the disk and the index on thedrum, The device illustrated is designed for testing tensions ofrelatively small magnitude, for example tensions ranging from 10 tograms. 'lBy the selection of stronger springs 21, it is obvious thatgreater tensions can be measured similarly.

The embodiment of the invention illustrated and described herein issubject to such modifications and changes as may fall withclaims.

][ claimza v 1. A device of the class described, comprising-a handlehaving a fork at one end, a hol low drum pivotally supported in saidfork so "as to turn about its axis of symmetry, a air of spacedthread-engaging members fixe on a third threadengaging member mounted onsaid drum and movable between said pair of members, a

spring within said drum tending to rotate it in one direction, and afinger piece on said drum to facilitate rotation thereof against saidspring.

2. A device of the class described, comprising a handle having a fork atone end, a pair of-pointed pivot members adj ustably mounted in saidfork, a hollow drum rotatably supported by said members to turn aboutits axis of symmetry, a pair of ping projecting from the periphery ofsaid drum and engageable with said handle to limit the angleof rotationof. said drum, a pair of thread-engaging members mounted on thefurcations respec-.

tively, a third thread-engaging member mounted on said drum and movablebetween said pair, and a spring within said drum tending to rotate saiddrum.

3. A device of the class described, comprising a handle having a forkedextension at one end thereof consistingof a pair of spaced disks inparallel planes, central pivot mem-'' bers extending through said disks,a hollow drum rotatably mounted on said pivots between said disks,spring means within said drum forimpressing a torque on said drum, apair of angularly spaced pins projecting from the periphery of said drumand engageable with said handle to limit the rotation of said drum, apair of peripherally grooved signature.

ERNEST COOK.

